


<!DOCTYPE html>
<html>
    <head lang="en">
        <meta charset="UTF-8">
        <title></title>
        <style>
        
        </style>

    </head>
    <body>
            <script type="text/javascript">
             var patt1=new RegExp("e");
            //  <!-- exec()检索字符串中的指定值。返回值是被找到的值。如果没有发现匹配，则返回 null。-->
            document.write(patt1.exec("The best things in life are free")); 
            </script>
       

    </body>
</html>